The invention relates to a tube mill partition with a material ball filing with a front slotted wall and a downstream rear wall, the slotted wall passing radially inwards into a central part with a central air passage opening and a lattice, whilst roughly radially oriented buckets are located between the slotted wall and the rear wall.
Such tube mill partitions are generally known, reference being made in exemplified manner to German Patent 24 47 262. It was standard practice with such known partitions, when used as a transfer or discharge wall in a tube mill, to provide in the central area of the partition a downstream, conically narrowing air passage opening. The truncated cone-shaped part of said air passage opening serves to transfer to the following tube mill chamber the grinding material raised by the lifting buckets as a result of the truncated cone-shaped guide plates.
Thus, this design of the air passage opening with a truncated cone-shaped cross-section has a damming back effect on the air blown and passed axially through the tube mill with a pressure and speed reducing effect, said energy loss having hitherto been accepted due to the transfer effect for the grinding material. However, in corresponding tube mills, as shown by German Patent 24 47 262, optionally intermediate walls have been inserted in the partition in order to regulate the material flow through a corresponding damming back effect.
Since for some time the grinding material supplied to the tube mills, such as e.g. cement clinker has undergone a primary crushing before the tube mill, said grinding or crushing material passes into the mill with a smaller particle size. Therefore ever greater significance is attached to the air flow present in the tube mill, so that every effort is made to keep the volume of the air flow as large as possible, without having to accept excessive energy losses through the pressure or flow reduction on passing through the tube mill.